1. Field
The present disclosure relates to zoom lens systems, interchangeable lens apparatuses, and camera systems.
2. Description of the Related Art
In recent years, interchangeable-lens type digital camera systems (also referred to simply as “camera systems”, hereinafter) have been spreading rapidly. Such interchangeable-lens type digital camera systems realize: taking of high-sensitive and high-quality images; high-speed focusing and high-speed image processing after image taking; and easy replacement of an interchangeable lens apparatus in accordance with a desired scene. Meanwhile, an interchangeable lens apparatus having a zoom lens system that forms an optical image with variable magnification is popular because it allows free change of focal length.
Japanese Laid-Open Patent Publication No. 2012-083432 discloses a zoom lens having a six-unit construction of negative, positive, negative, positive, negative, and positive, in which zooming is performed by moving the first to fifth lens units from a wide-angle limit to a telephoto limit, and focusing is performed by moving the fifth lens unit.
Japanese Laid-Open Patent Publication No. 2008-233585 discloses an optical equipment having a five-unit construction of negative, positive, negative, positive, and positive, in which zooming is performed by moving the first to fourth lens units from a wide-angle limit to a telephoto limit, and focusing is performed by moving an object-side part of the second lens unit.
Japanese Laid-Open Patent Publication No. 2012-068303 discloses an imaging lens having a four-unit construction of negative, positive, negative, and positive, in which zooming is performed by moving the respective lens units from a wide-angle limit to a telephoto limit, and focusing is performed by moving an object-side part of the second lens unit.